package com.fupeng.jd;

import static org.junit.Assert.*;

import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;

import org.junit.Test;
public class Flower {
	
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		List<Index> list = new LinkedList<Index>();
		while(scanner.hasNextLine()){
			Index index = new Index(scanner.nextLine(), scanner.nextLine());
			list.add(index);
		}
		for(Index i:list)
			solution(i);
	}

	@Test
	public void testName() throws Exception {
		int i=0;
		Integer j = new Integer(0);
		System.out.println(i==j);
		System.out.println(j.equals(i));
	}
	
	private static final void solution(Index index) {
		char[] s = new char[2];
		char[] t = new char[2];
		for(int i=0;i<2;i++){
			s[i]=index.getFirst().charAt(i);
			t[i]=index.getSecond().charAt(i);
		}
		
		char[] s1 = new char[2];
		if(s[0]<t[0]&&s[1]>t[1]){
			s1[0]=(char) (s[0]+s[1]-t[1]);
			s1[1]=t[1];
			int RD = s[1]-s1[1];
			int R = t[0]-s1[0];
			System.out.println(RD+R);
			for(int i=0;i<RD;i++)
				System.out.println("RD");
			for(int i=0;i<R;i++)
				System.out.println("R");
		}else if (s[0]<t[0]&&s[1]<t[1]) {
			s1[0]=(char) (s[0]+t[1]-s[1]);
			s1[1]=t[1];
			int RU=s1[1]-s[1];
			int R = t[0]-s1[0];
			System.out.println(RU+R);
			for(int i=0;i<RU;i++)
				System.out.println("RU");
			for(int i=0;i<R;i++)
				System.out.println("R");
		}else if (s[0]>t[0]&&s[1]<t[1]) {
			s1[0]=(char) (s[0]-(t[1]-s[1]));
			s1[1]=(char) (s[1]+(t[1]-s[1]));
			int LU=s1[1]-s[1];
			if(s1[0]==t[0]){
				int U=t[1]-s1[1];
				System.out.println(LU+U);
				for(int i=0;i<LU;i++)
					System.out.println("LU");
				for(int i=0;i<U;i++)
					System.out.println("U");
			}else{
				int L = s1[0]-t[0];
				System.out.println(LU+L);
				for(int i=0;i<LU;i++)
					System.out.println("LU");
				for(int i=0;i<L;i++)
					System.out.println("L");
			}
				
			
			
			
		
			
		}
	}

}

class Index{
	private String first;
	private String second;
	public Index(String first, String second) {
		super();
		this.first = first;
		this.second = second;
	}
	public String getFirst() {
		return first;
	}
	public String getSecond() {
		return second;
	}
}